import './style.css';

// ===== State =====
const state = {
    headers: [],
    rows: [],
    filePath: '',
    cursor: { row: 0, col: 0 },
    selection: null, // { startRow, startCol, endRow, endCol }
    colWidths: [],   // pixel widths per column
    isSelecting: false,
    editingHeader: -1,
    formulaBarFocused: false,
    formulaBarFromTable: false,
};

// ===== DOM refs =====
const $ = (sel) => document.querySelector(sel);
const tableHead = $('#table-head');
const tableBody = $('#table-body');
const formulaBar = $('#formula-bar');
const cellRef = $('#cell-ref');
const statusText = $('#status-text');
const commandPalette = $('#command-palette');
const commandInput = $('#command-input');
const commandList = $('#command-list');
const overlay = $('#overlay');
const tableContainer = $('#table-container');
const sortModal = $('#sort-modal');
const sortInput = $('#sort-columns-input');
const sortAutocomplete = $('#sort-autocomplete');
const sortConfirmBtn = $('#sort-confirm-btn');
const sortCancelBtn = $('#sort-cancel-btn');

// Default column width
const DEFAULT_COL_WIDTH = 120;
const MIN_COL_WIDTH = 40;
const MAX_BEST_FIT = 150;

// ===== Helpers =====
function colLabel(i) {
    // A, B, C ... Z, AA, AB ...
    let s = '';
    let n = i;
    do {
        s = String.fromCharCode(65 + (n % 26)) + s;
        n = Math.floor(n / 26) - 1;
    } while (n >= 0);
    return s;
}

function cellRefStr(r, c) {
    return colLabel(c) + (r + 1);
}

function normalizeSelection() {
    if (!state.selection) return null;
    const { startRow, startCol, endRow, endCol } = state.selection;
    return {
        r1: Math.min(startRow, endRow),
        c1: Math.min(startCol, endCol),
        r2: Math.max(startRow, endRow),
        c2: Math.max(startCol, endCol),
    };
}

function isCellSelected(r, c) {
    const sel = normalizeSelection();
    if (!sel) return r === state.cursor.row && c === state.cursor.col;
    return r >= sel.r1 && r <= sel.r2 && c >= sel.c1 && c <= sel.c2;
}

function getCellValue(r, c) {
    if (r < 0 || r >= state.rows.length) return '';
    if (c < 0 || !state.rows[r] || c >= state.rows[r].length) return '';
    return state.rows[r][c] || '';
}

function setCellValue(r, c, val) {
    // Ensure row exists
    while (state.rows.length <= r) state.rows.push([]);
    // Ensure columns exist
    while (state.rows[r].length <= c) state.rows[r].push('');
    state.rows[r][c] = val;
}

function ensureGridSize() {
    const numCols = state.headers.length;
    for (let i = 0; i < state.rows.length; i++) {
        while (state.rows[i].length < numCols) state.rows[i].push('');
    }
}

function setStatus(msg) {
    statusText.textContent = msg;
}

// ===== Rendering =====
function render() {
    renderHead();
    renderBody();
    updateFormulaBar();
    updateCellRef();
}

function renderHead() {
    tableHead.innerHTML = '';
    const tr = document.createElement('tr');

    // Row number header
    const th0 = document.createElement('th');
    th0.className = 'row-number-header';
    th0.textContent = '';
    tr.appendChild(th0);

    state.headers.forEach((h, i) => {
        const th = document.createElement('th');
        th.style.width = (state.colWidths[i] || DEFAULT_COL_WIDTH) + 'px';
        th.style.position = 'relative';
        th.dataset.col = i;

        const content = document.createElement('div');
        content.className = 'header-content';

        const textSpan = document.createElement('span');
        textSpan.className = 'header-text';
        textSpan.textContent = h;
        content.appendChild(textSpan);

        th.appendChild(content);

        // Resize handle
        const handle = document.createElement('div');
        handle.className = 'col-resize-handle';
        handle.addEventListener('mousedown', (e) => startColResize(e, i));
        handle.addEventListener('dblclick', (e) => {
            e.stopPropagation();
            bestFitColumn(i);
        });
        th.appendChild(handle);

        // Double click to edit header
        th.addEventListener('dblclick', (e) => {
            if (e.target.classList.contains('col-resize-handle')) return;
            startHeaderEdit(i);
        });

        tr.appendChild(th);
    });

    tableHead.appendChild(tr);
}

function renderBody() {
    tableBody.innerHTML = '';
    const numCols = state.headers.length;

    state.rows.forEach((row, r) => {
        const tr = document.createElement('tr');

        // Row number
        const tdNum = document.createElement('td');
        tdNum.className = 'row-number';
        tdNum.textContent = r + 1;
        tr.appendChild(tdNum);

        for (let c = 0; c < numCols; c++) {
            const td = document.createElement('td');
            td.style.width = (state.colWidths[c] || DEFAULT_COL_WIDTH) + 'px';
            td.textContent = row[c] || '';
            td.dataset.row = r;
            td.dataset.col = c;

            if (isCellSelected(r, c)) {
                td.classList.add('selected');
            }
            if (r === state.cursor.row && c === state.cursor.col) {
                td.classList.add('cursor-cell');
            }

            tr.appendChild(td);
        }

        tableBody.appendChild(tr);
    });
}

function updateSelectionClasses() {
    const tds = tableBody.querySelectorAll('td[data-row]');
    tds.forEach(td => {
        const r = parseInt(td.dataset.row);
        const c = parseInt(td.dataset.col);
        td.classList.toggle('selected', isCellSelected(r, c));
        td.classList.toggle('cursor-cell', r === state.cursor.row && c === state.cursor.col);
    });
    updateFormulaBar();
    updateCellRef();
}

function updateFormulaBar() {
    if (!state.formulaBarFocused) {
        formulaBar.value = getCellValue(state.cursor.row, state.cursor.col);
    }
}

function updateCellRef() {
    if (state.headers.length > 0 && state.rows.length > 0) {
        cellRef.textContent = cellRefStr(state.cursor.row, state.cursor.col);
    } else {
        cellRef.textContent = '';
    }
}

function scrollCursorIntoView() {
    const td = tableBody.querySelector(
        `td[data-row="${state.cursor.row}"][data-col="${state.cursor.col}"]`
    );
    if (td) {
        td.scrollIntoView({ block: 'nearest', inline: 'nearest' });
    }
}

// ===== Header editing =====
function startHeaderEdit(colIndex) {
    state.editingHeader = colIndex;
    const ths = tableHead.querySelectorAll('th');
    const th = ths[colIndex + 1]; // +1 for row number header
    if (!th) return;

    const content = th.querySelector('.header-content');
    content.innerHTML = '';

    const input = document.createElement('input');
    input.type = 'text';
    input.className = 'header-edit-input';
    input.value = state.headers[colIndex];
    content.appendChild(input);
    input.focus();
    input.select();

    const finish = () => {
        state.headers[colIndex] = input.value;
        state.editingHeader = -1;
        renderHead();
    };

    input.addEventListener('blur', finish);
    input.addEventListener('keydown', (e) => {
        if (e.key === 'Enter') { input.blur(); }
        if (e.key === 'Escape') {
            input.value = state.headers[colIndex]; // revert
            input.blur();
        }
        e.stopPropagation();
    });
}

// ===== Column resizing =====
let resizeState = null;

function startColResize(e, colIndex) {
    e.preventDefault();
    e.stopPropagation();
    const startX = e.clientX;
    const startWidth = state.colWidths[colIndex] || DEFAULT_COL_WIDTH;

    resizeState = { colIndex, startX, startWidth };

    const handle = e.target;
    handle.classList.add('active');

    const onMove = (ev) => {
        const diff = ev.clientX - startX;
        const newWidth = Math.max(MIN_COL_WIDTH, startWidth + diff);
        state.colWidths[colIndex] = newWidth;

        // Update widths live
        const ths = tableHead.querySelectorAll('th');
        if (ths[colIndex + 1]) ths[colIndex + 1].style.width = newWidth + 'px';

        const allTds = tableBody.querySelectorAll(`td[data-col="${colIndex}"]`);
        allTds.forEach(td => td.style.width = newWidth + 'px');
    };

    const onUp = () => {
        handle.classList.remove('active');
        document.removeEventListener('mousemove', onMove);
        document.removeEventListener('mouseup', onUp);
        resizeState = null;
    };

    document.addEventListener('mousemove', onMove);
    document.addEventListener('mouseup', onUp);
}

function bestFitColumn(colIndex) {
    // Measure the widest content in this column
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    ctx.font = '13px -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif';

    let maxW = ctx.measureText(state.headers[colIndex] || '').width;

    for (const row of state.rows) {
        const val = row[colIndex] || '';
        const w = ctx.measureText(val).width;
        if (w > maxW) maxW = w;
    }

    // Add padding
    const fitted = Math.ceil(maxW) + 24; // 12px padding each side
    const width = Math.max(fitted, MAX_BEST_FIT);
    state.colWidths[colIndex] = width;
    render();
}

function bestFitAllColumns() {
    for (let i = 0; i < state.headers.length; i++) {
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        ctx.font = '13px -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif';

        let maxW = ctx.measureText(state.headers[i] || '').width;
        for (const row of state.rows) {
            const w = ctx.measureText(row[i] || '').width;
            if (w > maxW) maxW = w;
        }

        const fitted = Math.ceil(maxW) + 24;
        state.colWidths[i] = Math.max(fitted, MAX_BEST_FIT);
    }
    render();
}

// ===== Cell click & drag selection =====
tableBody.addEventListener('mousedown', (e) => {
    const td = e.target.closest('td[data-row]');
    if (!td) return;

    const r = parseInt(td.dataset.row);
    const c = parseInt(td.dataset.col);

    // Commit formula bar if it was focused
    if (state.formulaBarFocused) {
        commitFormulaBar();
    }

    if (e.shiftKey) {
        // Extend selection
        state.selection = {
            startRow: state.cursor.row,
            startCol: state.cursor.col,
            endRow: r,
            endCol: c
        };
    } else {
        state.cursor = { row: r, col: c };
        state.selection = { startRow: r, startCol: c, endRow: r, endCol: c };
    }

    state.isSelecting = true;
    updateSelectionClasses();
});

document.addEventListener('mousemove', (e) => {
    if (!state.isSelecting) return;
    const td = e.target.closest('td[data-row]');
    if (!td) return;

    const r = parseInt(td.dataset.row);
    const c = parseInt(td.dataset.col);

    if (state.selection) {
        state.selection.endRow = r;
        state.selection.endCol = c;
    }

    updateSelectionClasses();
});

document.addEventListener('mouseup', () => {
    state.isSelecting = false;
});

// ===== Keyboard navigation =====
function moveCursor(dr, dc, shift) {
    if (shift) {
        if (!state.selection) {
            state.selection = {
                startRow: state.cursor.row,
                startCol: state.cursor.col,
                endRow: state.cursor.row,
                endCol: state.cursor.col
            };
        }
        const nr = Math.max(0, Math.min(state.rows.length - 1, state.selection.endRow + dr));
        const nc = Math.max(0, Math.min(state.headers.length - 1, state.selection.endCol + dc));
        state.selection.endRow = nr;
        state.selection.endCol = nc;
    } else {
        const nr = Math.max(0, Math.min(state.rows.length - 1, state.cursor.row + dr));
        const nc = Math.max(0, Math.min(state.headers.length - 1, state.cursor.col + dc));
        state.cursor = { row: nr, col: nc };
        state.selection = null;
    }
    updateSelectionClasses();
    scrollCursorIntoView();
}

document.addEventListener('keydown', (e) => {
    // Command palette
    if ((e.metaKey || e.ctrlKey) && e.key === 'p') {
        e.preventDefault();
        openCommandPalette();
        return;
    }

    // If command palette is open, don't handle other keys
    if (!commandPalette.classList.contains('hidden')) return;

    // If editing a header, don't interfere
    if (state.editingHeader >= 0) return;

    // If formula bar is focused, handle Enter/Escape
    if (state.formulaBarFocused) {
        if (e.key === 'Enter') {
            e.preventDefault();
            commitFormulaBar();
            if (state.formulaBarFromTable) {
                formulaBar.blur();
                tableContainer.focus();
            }
            return;
        }
        if (e.key === 'Escape') {
            e.preventDefault();
            cancelFormulaBar();
            formulaBar.blur();
            tableContainer.focus();
            return;
        }
        return; // Let normal typing happen in formula bar
    }

    // Shortcuts
    const meta = e.metaKey || e.ctrlKey;

    if (meta && e.key === 's') {
        e.preventDefault();
        executeCommand('save');
        return;
    }
    if (meta && e.key === 'c') {
        e.preventDefault();
        executeCommand('copy');
        return;
    }
    if (meta && e.key === 'x') {
        e.preventDefault();
        executeCommand('cut');
        return;
    }
    if (meta && e.key === 'v') {
        e.preventDefault();
        executeCommand('paste');
        return;
    }
    if (meta && e.key === 'o') {
        e.preventDefault();
        executeCommand('open');
        return;
    }

    // Arrow keys
    if (e.key === 'ArrowUp') { e.preventDefault(); moveCursor(-1, 0, e.shiftKey); return; }
    if (e.key === 'ArrowDown') { e.preventDefault(); moveCursor(1, 0, e.shiftKey); return; }
    if (e.key === 'ArrowLeft') { e.preventDefault(); moveCursor(0, -1, e.shiftKey); return; }
    if (e.key === 'ArrowRight') { e.preventDefault(); moveCursor(0, 1, e.shiftKey); return; }

    // Tab
    if (e.key === 'Tab') {
        e.preventDefault();
        moveCursor(0, e.shiftKey ? -1 : 1, false);
        return;
    }

    // Enter moves down
    if (e.key === 'Enter') {
        e.preventDefault();
        moveCursor(1, 0, false);
        return;
    }

    // Cmd+Backspace deletes rows
    if (meta && e.key === 'Backspace') {
        e.preventDefault();
        executeCommand('delete-row');
        return;
    }

    // Delete/Backspace clears selected cells
    if (e.key === 'Delete' || e.key === 'Backspace') {
        e.preventDefault();
        clearSelectedCells();
        return;
    }

    // Escape clears selection
    if (e.key === 'Escape') {
        state.selection = null;
        updateSelectionClasses();
        return;
    }

    // Typing a printable character: focus formula bar and start editing
    if (e.key.length === 1 && !meta && !e.altKey) {
        e.preventDefault();
        formulaBar.value = '';
        formulaBar.focus();
        state.formulaBarFocused = true;
        state.formulaBarFromTable = true;
        // Insert the typed character
        formulaBar.value = e.key;
        // Move cursor to end
        formulaBar.setSelectionRange(formulaBar.value.length, formulaBar.value.length);
        return;
    }
});

// ===== Formula bar =====
formulaBar.addEventListener('focus', () => {
    state.formulaBarFocused = true;
    // If not triggered by keyboard, this was a direct click
    if (!state.formulaBarFromTable) {
        formulaBar.value = getCellValue(state.cursor.row, state.cursor.col);
    }
});

formulaBar.addEventListener('blur', () => {
    state.formulaBarFocused = false;
    state.formulaBarFromTable = false;
});

function commitFormulaBar() {
    setCellValue(state.cursor.row, state.cursor.col, formulaBar.value);
    state.formulaBarFocused = false;
    state.formulaBarFromTable = false;
    render();
}

function cancelFormulaBar() {
    formulaBar.value = getCellValue(state.cursor.row, state.cursor.col);
    state.formulaBarFocused = false;
    state.formulaBarFromTable = false;
}

// ===== Selection data extraction =====
function getSelectedData() {
    const sel = normalizeSelection();
    if (!sel) {
        return {
            headers: [state.headers[state.cursor.col]],
            rows: [[getCellValue(state.cursor.row, state.cursor.col)]],
            isSingleCol: true
        };
    }
    const headers = [];
    for (let c = sel.c1; c <= sel.c2; c++) {
        headers.push(state.headers[c] || '');
    }
    const rows = [];
    for (let r = sel.r1; r <= sel.r2; r++) {
        const row = [];
        for (let c = sel.c1; c <= sel.c2; c++) {
            row.push(getCellValue(r, c));
        }
        rows.push(row);
    }
    return {
        headers,
        rows,
        isSingleCol: sel.c1 === sel.c2
    };
}

function clearSelectedCells() {
    const sel = normalizeSelection();
    if (!sel) {
        setCellValue(state.cursor.row, state.cursor.col, '');
    } else {
        for (let r = sel.r1; r <= sel.r2; r++) {
            for (let c = sel.c1; c <= sel.c2; c++) {
                setCellValue(r, c, '');
            }
        }
    }
    render();
}

// ===== Commands =====
let commands = [];

async function loadCommands() {
    try {
        commands = await window.go.main.CommandRegistry.GetCommands();
    } catch (e) {
        console.error('Failed to load commands:', e);
        // Fallback commands
        commands = [
            { ID: 'copy', Name: 'Copy', Shortcut: 'Cmd+C' },
            { ID: 'cut', Name: 'Cut', Shortcut: 'Cmd+X' },
            { ID: 'copy-markdown', Name: 'Copy as Markdown', Shortcut: '' },
            { ID: 'copy-jira', Name: 'Copy as Jira', Shortcut: '' },
            { ID: 'paste', Name: 'Paste', Shortcut: 'Cmd+V' },
            { ID: 'resize-all', Name: 'Resize All Columns', Shortcut: '' },
            { ID: 'open', Name: 'Open File', Shortcut: 'Cmd+O' },
            { ID: 'save', Name: 'Save File', Shortcut: 'Cmd+S' },
            { ID: 'open-up', Name: 'Insert Row Above', Shortcut: '' },
            { ID: 'open-down', Name: 'Insert Row Below', Shortcut: '' },
            { ID: 'open-left', Name: 'Insert Column Left', Shortcut: '' },
            { ID: 'open-right', Name: 'Insert Column Right', Shortcut: '' },
            { ID: 'sort-asc', Name: 'Sort A-Z', Shortcut: '' },
            { ID: 'sort-desc', Name: 'Sort Z-A', Shortcut: '' },
            { ID: 'sort-advanced', Name: 'Sort Advanced', Shortcut: '' },
            { ID: 'match-row', Name: 'Match Row', Shortcut: '' },
            { ID: 'delete-row', Name: 'Delete Row', Shortcut: 'Cmd+Backspace' },
        ];
    }
}

function openCommandPalette() {
    commandPalette.classList.remove('hidden');
    overlay.classList.remove('hidden');
    commandInput.value = '';
    renderCommandList('');
    commandInput.focus();
}

function closeCommandPalette() {
    commandPalette.classList.add('hidden');
    overlay.classList.add('hidden');
    commandInput.value = '';
}

let activeCommandIndex = 0;

function renderCommandList(filter) {
    commandList.innerHTML = '';
    const lower = filter.toLowerCase();
    const filtered = commands
        .filter(c => c.Name.toLowerCase().includes(lower))
        .sort((a, b) => a.Name.toLowerCase().localeCompare(b.Name.toLowerCase()));

    activeCommandIndex = 0;

    filtered.forEach((cmd, i) => {
        const div = document.createElement('div');
        div.className = 'command-item' + (i === 0 ? ' active' : '');
        div.innerHTML = `<span class="cmd-name">${cmd.Name}</span>` +
            (cmd.Shortcut ? `<span class="cmd-shortcut">${cmd.Shortcut}</span>` : '');
        div.addEventListener('click', () => {
            closeCommandPalette();
            executeCommand(cmd.ID);
        });
        commandList.appendChild(div);
    });
}

commandInput.addEventListener('input', () => {
    renderCommandList(commandInput.value);
});

commandInput.addEventListener('keydown', (e) => {
    const items = commandList.querySelectorAll('.command-item');
    if (e.key === 'Escape') {
        e.preventDefault();
        closeCommandPalette();
        return;
    }
    if (e.key === 'ArrowDown') {
        e.preventDefault();
        if (items.length === 0) return;
        items[activeCommandIndex]?.classList.remove('active');
        activeCommandIndex = (activeCommandIndex + 1) % items.length;
        items[activeCommandIndex]?.classList.add('active');
        items[activeCommandIndex]?.scrollIntoView({ block: 'nearest' });
        return;
    }
    if (e.key === 'ArrowUp') {
        e.preventDefault();
        if (items.length === 0) return;
        items[activeCommandIndex]?.classList.remove('active');
        activeCommandIndex = (activeCommandIndex - 1 + items.length) % items.length;
        items[activeCommandIndex]?.classList.add('active');
        items[activeCommandIndex]?.scrollIntoView({ block: 'nearest' });
        return;
    }
    if (e.key === 'Enter') {
        e.preventDefault();
        const items = commandList.querySelectorAll('.command-item');
        if (items[activeCommandIndex]) {
            items[activeCommandIndex].click();
        }
        return;
    }
    e.stopPropagation();
});

overlay.addEventListener('click', () => {
    if (!commandPalette.classList.contains('hidden')) closeCommandPalette();
    if (!sortModal.classList.contains('hidden')) closeSortAdvanced();
});

// ===== Command execution =====
async function executeCommand(id) {
    switch (id) {
        case 'copy': await doCopy(); break;
        case 'cut': await doCut(); break;
        case 'copy-markdown': await doCopyMarkdown(); break;
        case 'copy-jira': await doCopyJira(); break;
        case 'paste': await doPaste(); break;
        case 'resize-all': bestFitAllColumns(); setStatus('All columns resized'); break;
        case 'open': await doOpen(); break;
        case 'save': await doSave(); break;
        case 'open-up': doInsertRowAbove(); break;
        case 'open-down': doInsertRowBelow(); break;
        case 'open-left': doInsertColLeft(); break;
        case 'open-right': doInsertColRight(); break;
        case 'sort-asc': doSort(true); break;
        case 'sort-desc': doSort(false); break;
        case 'sort-advanced': openSortAdvanced(); break;
        case 'match-row': doMatchRow(); break;
        case 'delete-row': doDeleteRow(); break;
    }
}

async function doCopy() {
    const data = getSelectedData();
    let text;
    if (data.isSingleCol) {
        try {
            text = await window.go.main.App.FormatAsSingleColumn(data.rows);
        } catch {
            text = data.rows.map(r => r[0]).join('\n');
        }
    } else {
        try {
            text = await window.go.main.App.FormatRowsAsCSV(data.rows);
        } catch {
            text = data.rows.map(r => r.join(',')).join('\n');
        }
    }
    await navigator.clipboard.writeText(text);
    setStatus('Copied to clipboard');
}

async function doCut() {
    await doCopy();
    clearSelectedCells();
    setStatus('Cut to clipboard');
}

async function doCopyMarkdown() {
    const data = getSelectedData();
    let text;
    try {
        text = await window.go.main.App.FormatAsMarkdown(data.headers, data.rows);
    } catch {
        text = '(Markdown format unavailable)';
    }
    await navigator.clipboard.writeText(text);
    setStatus('Copied as Markdown');
}

async function doCopyJira() {
    const data = getSelectedData();
    let text;
    try {
        text = await window.go.main.App.FormatAsJira(data.headers, data.rows);
    } catch {
        text = '(Jira format unavailable)';
    }
    await navigator.clipboard.writeText(text);
    setStatus('Copied as Jira');
}

async function doPaste() {
    let text;
    try {
        text = await navigator.clipboard.readText();
    } catch {
        setStatus('Failed to read clipboard');
        return;
    }

    if (!text || !text.trim()) {
        setStatus('Clipboard is empty');
        return;
    }

    const lines = text.trim().split('\n');

    // Check if it looks like CSV: multi-line, consistent comma-separated columns
    let isCSV = false;
    if (lines.length > 1) {
        // Count commas outside quotes for each line
        const colCounts = lines.map(line => {
            let count = 1;
            let inQuote = false;
            for (const ch of line) {
                if (ch === '"') inQuote = !inQuote;
                else if (ch === ',' && !inQuote) count++;
            }
            return count;
        });
        // Check if all lines have the same column count and > 1
        const first = colCounts[0];
        if (first > 1 && colCounts.every(c => c === first)) {
            // Also check no spaces before commas (heuristic for CSV-like)
            isCSV = true;
        }
    }

    let pasteRows;
    if (isCSV) {
        try {
            const parsed = await window.go.main.App.ParseCSVString(text);
            // Combine headers and rows since we're pasting into cells
            pasteRows = [parsed.Headers, ...parsed.Rows];
        } catch {
            // Fallback: split by comma
            pasteRows = lines.map(l => l.split(','));
        }
    } else {
        // Each line is a single-column row
        pasteRows = lines.map(l => [l]);
    }

    // Place at cursor position
    const startRow = state.cursor.row;
    const startCol = state.cursor.col;

    for (let r = 0; r < pasteRows.length; r++) {
        for (let c = 0; c < pasteRows[r].length; c++) {
            const targetRow = startRow + r;
            const targetCol = startCol + c;
            // Extend grid if needed
            while (state.rows.length <= targetRow) state.rows.push(new Array(state.headers.length).fill(''));
            while (state.headers.length <= targetCol) {
                state.headers.push(colLabel(state.headers.length));
                state.colWidths.push(DEFAULT_COL_WIDTH);
                for (const row of state.rows) row.push('');
            }
            setCellValue(targetRow, targetCol, pasteRows[r][c]);
        }
    }

    render();
    setStatus(`Pasted ${pasteRows.length} rows`);
}

async function doOpen() {
    let filePath;
    try {
        filePath = await window.go.main.App.OpenFileDialog();
    } catch (e) {
        setStatus('Open cancelled');
        return;
    }
    if (!filePath) {
        setStatus('Open cancelled');
        return;
    }
    await loadFile(filePath);
}

async function doSave() {
    if (state.filePath) {
        try {
            await window.go.main.App.SaveCurrentFile(state.headers, state.rows);
            setStatus('Saved: ' + state.filePath);
        } catch (e) {
            setStatus('Error saving: ' + e);
        }
    } else {
        let filePath;
        try {
            filePath = await window.go.main.App.SaveFileDialog();
        } catch {
            setStatus('Save cancelled');
            return;
        }
        if (!filePath) {
            setStatus('Save cancelled');
            return;
        }
        try {
            await window.go.main.App.SaveCSV(filePath, state.headers, state.rows);
            state.filePath = filePath;
            setStatus('Saved: ' + filePath);
        } catch (e) {
            setStatus('Error saving: ' + e);
        }
    }
}

function doInsertRowAbove() {
    const r = state.cursor.row;
    const newRow = new Array(state.headers.length).fill('');
    state.rows.splice(r, 0, newRow);
    render();
    setStatus('Inserted row above');
}

function doInsertRowBelow() {
    const r = state.cursor.row;
    const newRow = new Array(state.headers.length).fill('');
    state.rows.splice(r + 1, 0, newRow);
    state.cursor.row = r + 1;
    render();
    setStatus('Inserted row below');
}

function doInsertColLeft() {
    const c = state.cursor.col;
    state.headers.splice(c, 0, colLabel(state.headers.length));
    state.colWidths.splice(c, 0, DEFAULT_COL_WIDTH);
    for (const row of state.rows) {
        row.splice(c, 0, '');
    }
    render();
    setStatus('Inserted column left');
}

function doInsertColRight() {
    const c = state.cursor.col + 1;
    state.headers.splice(c, 0, colLabel(state.headers.length));
    state.colWidths.splice(c, 0, DEFAULT_COL_WIDTH);
    for (const row of state.rows) {
        row.splice(c, 0, '');
    }
    state.cursor.col = c;
    render();
    setStatus('Inserted column right');
}

// ===== Match & Delete Row =====
function doMatchRow() {
    const col = state.cursor.col;
    const val = getCellValue(state.cursor.row, col);
    const matchingRows = [];
    for (let r = 0; r < state.rows.length; r++) {
        if ((state.rows[r][col] || '') === val) {
            matchingRows.push(r);
        }
    }
    if (matchingRows.length === 0) {
        setStatus('No matching rows');
        return;
    }
    // Select from first to last matching row, spanning all columns
    const first = matchingRows[0];
    const last = matchingRows[matchingRows.length - 1];
    state.cursor = { row: first, col: 0 };
    state.selection = {
        startRow: first,
        startCol: 0,
        endRow: last,
        endCol: state.headers.length - 1,
    };
    updateSelectionClasses();
    scrollCursorIntoView();
    const colName = state.headers[col] || colLabel(col);
    setStatus(`${matchingRows.length} row(s) matching ${colName} = "${val}"`);
}

function doDeleteRow() {
    const sel = normalizeSelection();
    let startRow, endRow;
    if (sel) {
        startRow = sel.r1;
        endRow = sel.r2;
    } else {
        startRow = state.cursor.row;
        endRow = state.cursor.row;
    }
    const count = endRow - startRow + 1;
    state.rows.splice(startRow, count);
    // Ensure at least one row remains
    if (state.rows.length === 0) {
        state.rows.push(new Array(state.headers.length).fill(''));
    }
    // Adjust cursor
    state.cursor.row = Math.min(startRow, state.rows.length - 1);
    state.selection = null;
    render();
    setStatus(`Deleted ${count} row(s)`);
}

// ===== Sorting =====
function doSort(ascending) {
    const col = state.cursor.col;
    state.rows.sort((a, b) => {
        const va = (a[col] || '').toLowerCase();
        const vb = (b[col] || '').toLowerCase();
        return ascending ? va.localeCompare(vb, undefined, { numeric: true })
                         : vb.localeCompare(va, undefined, { numeric: true });
    });
    render();
    setStatus(`Sorted by ${state.headers[col] || colLabel(col)} ${ascending ? 'A-Z' : 'Z-A'}`);
}

// ===== Sort Advanced Modal =====
let acIndex = -1;

function openSortAdvanced() {
    sortModal.classList.remove('hidden');
    overlay.classList.remove('hidden');
    sortInput.value = '';
    hideSortAutocomplete();
    sortInput.focus();
}

function closeSortAdvanced() {
    sortModal.classList.add('hidden');
    overlay.classList.add('hidden');
    sortInput.value = '';
    hideSortAutocomplete();
}

function hideSortAutocomplete() {
    sortAutocomplete.classList.add('hidden');
    sortAutocomplete.innerHTML = '';
    acIndex = -1;
}

function getCurrentToken() {
    const val = sortInput.value;
    const cursor = sortInput.selectionStart;
    const before = val.substring(0, cursor);
    const lastComma = before.lastIndexOf(',');
    return {
        text: before.substring(lastComma + 1).trim(),
        start: lastComma + 1,
        cursorPos: cursor,
    };
}

function getAlreadyChosen() {
    const parts = sortInput.value.split(',');
    const cursor = sortInput.selectionStart;
    const before = sortInput.value.substring(0, cursor);
    const tokenIdx = before.split(',').length - 1;
    return parts
        .map(p => p.trim().toLowerCase())
        .filter((_, i) => i !== tokenIdx)
        .filter(p => p.length > 0);
}

function updateSortAutocomplete() {
    const { text } = getCurrentToken();
    const lower = text.toLowerCase();
    const chosen = getAlreadyChosen();

    const matches = state.headers
        .filter(h => h.toLowerCase().includes(lower))
        .filter(h => !chosen.includes(h.toLowerCase()))
        .sort((a, b) => a.toLowerCase().localeCompare(b.toLowerCase()));

    if (matches.length === 0 || (matches.length === 1 && matches[0].toLowerCase() === lower)) {
        hideSortAutocomplete();
        return;
    }

    sortAutocomplete.innerHTML = '';
    sortAutocomplete.classList.remove('hidden');
    acIndex = -1;

    matches.forEach((name, i) => {
        const div = document.createElement('div');
        div.className = 'ac-item';
        div.textContent = name;
        div.addEventListener('mousedown', (e) => {
            e.preventDefault(); // keep focus on input
            applySortCompletion(name);
        });
        sortAutocomplete.appendChild(div);
    });
}

function applySortCompletion(name) {
    const val = sortInput.value;
    const cursor = sortInput.selectionStart;
    const before = val.substring(0, cursor);
    const after = val.substring(cursor);
    const lastComma = before.lastIndexOf(',');
    const prefix = before.substring(0, lastComma + 1);
    const spacing = lastComma >= 0 ? ' ' : '';
    const newVal = prefix + spacing + name + after;
    sortInput.value = newVal;
    const newCursor = (prefix + spacing + name).length;
    sortInput.setSelectionRange(newCursor, newCursor);
    hideSortAutocomplete();
    sortInput.focus();
}

function confirmSortAdvanced() {
    const names = sortInput.value
        .split(',')
        .map(s => s.trim())
        .filter(s => s.length > 0);

    const colIndices = [];
    for (const name of names) {
        const idx = state.headers.findIndex(
            h => h.toLowerCase() === name.toLowerCase()
        );
        if (idx === -1) {
            setStatus(`Unknown column: "${name}"`);
            return;
        }
        colIndices.push(idx);
    }

    if (colIndices.length === 0) {
        setStatus('No columns specified');
        return;
    }

    state.rows.sort((a, b) => {
        for (const col of colIndices) {
            const va = (a[col] || '').toLowerCase();
            const vb = (b[col] || '').toLowerCase();
            const cmp = va.localeCompare(vb, undefined, { numeric: true });
            if (cmp !== 0) return cmp;
        }
        return 0;
    });

    closeSortAdvanced();
    render();
    setStatus('Sorted by ' + names.join(', '));
}

sortInput.addEventListener('input', updateSortAutocomplete);
sortInput.addEventListener('focus', updateSortAutocomplete);
sortInput.addEventListener('blur', () => {
    // Small delay to allow mousedown on ac-item to fire
    setTimeout(hideSortAutocomplete, 150);
});

sortInput.addEventListener('keydown', (e) => {
    const items = sortAutocomplete.querySelectorAll('.ac-item');

    if (e.key === 'Escape') {
        e.preventDefault();
        e.stopPropagation();
        if (!sortAutocomplete.classList.contains('hidden')) {
            hideSortAutocomplete();
        } else {
            closeSortAdvanced();
        }
        return;
    }

    if (e.key === 'Enter') {
        e.preventDefault();
        e.stopPropagation();
        if (acIndex >= 0 && items[acIndex]) {
            applySortCompletion(items[acIndex].textContent);
        } else {
            confirmSortAdvanced();
        }
        return;
    }

    if (e.key === 'ArrowDown' && items.length > 0) {
        e.preventDefault();
        if (acIndex >= 0) items[acIndex]?.classList.remove('active');
        acIndex = (acIndex + 1) % items.length;
        items[acIndex]?.classList.add('active');
        items[acIndex]?.scrollIntoView({ block: 'nearest' });
        return;
    }

    if (e.key === 'ArrowUp' && items.length > 0) {
        e.preventDefault();
        if (acIndex >= 0) items[acIndex]?.classList.remove('active');
        acIndex = (acIndex - 1 + items.length) % items.length;
        items[acIndex]?.classList.add('active');
        items[acIndex]?.scrollIntoView({ block: 'nearest' });
        return;
    }

    e.stopPropagation();
});

sortConfirmBtn.addEventListener('click', confirmSortAdvanced);
sortCancelBtn.addEventListener('click', closeSortAdvanced);

// ===== File loading =====
async function loadFile(filePath) {
    try {
        const data = await window.go.main.App.LoadCSV(filePath);
        state.headers = data.Headers || [];
        state.rows = data.Rows || [];
        state.filePath = data.FilePath || filePath;
        state.cursor = { row: 0, col: 0 };
        state.selection = null;
        state.colWidths = state.headers.map(() => DEFAULT_COL_WIDTH);
        ensureGridSize();
        render();
        setStatus('Loaded: ' + filePath);
    } catch (e) {
        setStatus('Error loading: ' + e);
    }
}

function loadEmptySheet() {
    const cols = 10;
    const rows = 30;
    state.headers = Array.from({ length: cols }, (_, i) => colLabel(i));
    state.rows = Array.from({ length: rows }, () => new Array(cols).fill(''));
    state.colWidths = new Array(cols).fill(DEFAULT_COL_WIDTH);
    state.cursor = { row: 0, col: 0 };
    state.selection = null;
    state.filePath = '';
    render();
}

// ===== File drop =====
function setupFileDrop() {
    try {
        window.runtime.EventsOn('file-dropped', (filePath) => {
            if (filePath && filePath.toLowerCase().endsWith('.csv')) {
                loadFile(filePath);
            } else if (filePath) {
                // Try to load anyway
                loadFile(filePath);
            }
        });
    } catch (e) {
        console.warn('File drop events not available:', e);
    }
}

// ===== Init =====
async function init() {
    await loadCommands();
    setupFileDrop();
    loadEmptySheet();
}

init();